1. Field of the Invention
The present invention relates to a casting apparatus for preparing uranium ingots by melting uranium deposits. More specifically, the present invention relates to an ingot-casting apparatus using uranium deposits wherein uranium ingots can be continuously prepared in a single casting apparatus.
2. Description of the Related Art
Methods for extracting recycled uranium from spent nuclear fuels left behind after incinerated in a furnace include electro-refining technologies for temporarily storing or recycling uranium, comprising depositing uranium on a graphite cathode as a uranium electro-refining cathode to produce uranium deposits thereon and forming ingots from the deposits to recover uranium therefrom.
Uranium-ingot casting apparatuses prepare uranium ingots by melting uranium deposits recovered from a salt-distillation apparatus. Uranium deposits contain highly corrosive salts. For this reason, this melting process should be carried out under vacuum or inert gas atmosphere in order to prevent salts produced during the melting process from corroding neighboring devices.
In addition, uranium ingot casting apparatuses emit a great deal of salt in a gas phase, when heated to about 1,300° C. which is above the melting point of uranium. Accordingly, the apparatuses require a salt-removing means for separating the salt from the uranium deposits by capturing the salt, followed by cooling and solidifying.
An INL (Idaho National Laboratory) ingot casting apparatus capable of satisfying this requirement involves a batch-type process wherein one ingot is prepared in a single process, by placing uranium deposits in a crucible in an ingot vacuum chamber, melting the uranium deposits through heating, cooling the crucible to obtain an ingot, and separating the ingot from the crucible.
Such a batch-type ingot casting apparatus uses a single crucible, thus making it impossible to treat large volumes of uranium deposits and disadvantageously having low production efficiency, and having structural limitations of increasing a unit amount of uranium deposits treated.
In addition, once an ingot-preparation operation is finished, the vacuum chamber should be opened to transport the produced ingot and salt from the vacuum chamber, and in the following operation to treat uranium deposits, the vacuum chamber should be out-gassed and an inert gas should then be supplied thereto, causing an increase in operation costs.